1. Field of the Invention
The present invention relates in general to guide rail assemblies used in assembly line and conveyor belt systems and, in particular, to a means for adjustably housing, gripping and connecting sequential conveyor guide rails.
2. Description of the Related Art
Clamps are commonly used to grip and connect guide rails which direct the travel of articles along a predetermined path of an assembly line or conveyor system. The articles are conveyed on a belt or track during the processing and packaging procedures of a typical manufacturer. Dependable fixation and alignment of the guide rails is important to ensure manufacturing efficiency and to minimize damage of the articles from inappropriate contact with the guide rails. Guide rail length is customized to conveyor length by the sequential alignment and connection of guide rail segments.
Early guide rail housing, gripping, and connecting means were characterized by a cross bar that incorporated a clamping device, as illustrated in FIG. 1. Abutting guide rails were then connected and secured to the cross bar by the clamping device. Clips and other retention means were also used to secure abutting guide rails. An advantage of incorporating a clip with a nut and bolt clamping device is that the nut is more easily rotated onto the bolt without causing simultaneous rotation of the bolt. That is, integral bolts eliminate the need to grasp the bolt in order to prevent its rotation while rotating the nut into the bolt shaft. However, a disadvantage of clips formed with or without the bolt, is that they tend to rotate out of position about the pivot point formed by the bolt in the cross bar, thereby causing misalignment of the guide rail in the conveyor system.
Exemplary of a recent development in the guide rail housing, gripping and connecting field is illustrated in FIG. 2, which teaches a guide rail clamp comprising upper and lower L-shaped cross bars of equal length. The upper and lower cross bars are inversely aligned to form a C-shaped groove section wherein abutting guide rails are housed. The upper and lower cross bars are detachably connected by a nut and bolt retention device to allow adjustment of the guide rails.
However, the prior art devices all have significant deficiencies. Specifically, once abutting guide rail segments are connected, any subsequent alteration of either guide rail segment (due to setup, modification, replacement, etc.) is difficult because, when the retention means is loosened, both guide rail segments become loosened. This results in three loose parts. Therefore, the task of altering a guide rail segment requires either two operators or one operator with significant difficulty and awkwardness. A second problem with the prior art resulted because the abutting guide rail segments are secured on each end by only a single retention mechanism. Thus, whenever the single retention mechanism is loosened to alter a guide rail segment, the abutting rail segment is correspondingly loosened. A third problem with the prior art resulted from conveyor lines having radius turns. That is, when a conveyor line having a radius turn is outwardly adjusted, a gap is created commensurate with the radius arc length. This gap interrupts the close alignment of sequential guide rails and can cause articles to snag or be otherwise damaged when within the gap.
One of the primary factors which has inhibited the creation of a truly successful guide rail housing, gripping, connecting means has been the fixation of the prior art on securing the abutting ends of sequential guide rail segments with only a single retention device. It is this fixation on a single retention device that has restricted the art to inefficient and awkward designs.